Automatic firearm.



G. TOBORG.

AUTOMATIC FIREARM.

APPLICATION IILEI) AUG. 16, 1909.

Patented Feb. 13, 1912.

2 SHEETS-SHEET 1.

G. TOBORG. AUTOMATIC FIREARM.

' APPLICATION FILED AUG. 16, 1909.

Patented Feb. 13,1912.

2 SHEETS-SHEET 2.

lhll vj zwlllflll "a i. Fill I I AI/iir YIII/IIIII/ UNITED STATES PATENT OFFICE. I

GEORGE TOIBORG, OF CHICAGO, ILLINOIS.

AUTOMATIC FIREARM.

To all whom it may concern: I

Be it known that I, GEORGE TOBORG, of Chicago, in the State of Illinois, have invented certain new, and useful Improvements in Automatic Firearms, of which the following is a specification.

My invention relates to automatic firearms in which the recoil operates to cock the hammer and eject the empty shell.

The objects of my improvements are: first, to provide a chambered frame or casing made rigid with the barrel in operation, the chamber being extended rearwardly in line with barrel and downwardly so as to inclose and conceal from view a sliding spring-pressed breech block, a cartridge magazine and other parts which are movable in operation within the chamber; second, to provide means designed to prevent clogging of the cartridges in their passage from the magazine to the barrel; third, to provide means outside the casing for manipulating the sliding breech-block inclosed within the casing to cock the hammer when desired; fourth, to simplify the construction by reducing the number of the working parts movable within the casing, and making them readily detachable; fifth, to provide the hammer with an automatic safety device which may be released from the outside of the casing when pulling the trigger; sixth, to provide the casing with a readily removable side-plate whereby the parts inclosed within the casing are made readily accessible for cleaning, oiling, etc. I attain these objects by the mechanism illustrated in the accompanying drawings in which Figure 1 is a side elevation showing the right hand side of a pistol containing my invention. Fig. 2 is a side elevation showing the left hand side of the pistol. Fig. 3 is a fragmentary side elevation with the side plate of the casing removed to show the parts within the casing, the parts being in the position which they occupy at the instant of firing. Fig. 4 is a longitudinal central, vertical section of the pistol showing the working parts in the reverse position to that seen in Fig. 3. Fig. 5 is a cross section of the casing of the pistol taken on a plane indicated by the line 5 5 of Fig. 3. Fig. 6 is a fragmentary horizontal section of the pistol taken on the plane indicated by the line6 6 of Fig. 3.

Similar signs marked on the drawings Specification of Letters Patent.

Application filed August 16, 1909.

Patented Feb. 13, 1912.

Serial No. 512,945.

. tion of the barrel and casing is rigid so that these parts shall be relatively immovable in operation, and these parts except the detachable side plate, are preferably made integral as of a single piece of forged steel.

The extension of the casing chamber rearward from the barrel is just sufiicient to cover the length of the breech-block C and its travel, and its section is large enough to more than cover the section of the bore of the barrel. The downward extension of said chamber is sufficient to receive the cartridge magazine and other parts working below the breech block.

The side plates of the casing are recessed at the top as shown at 6 (Figs. 3, 5), the recesses extending from the rear end of the barrel to the rear wall of the casing and forming a way in which the sliding breechblock C can play back and forth in said chamber, the forward movement being stopped against the rear end of the barrel and the rearward movement against the rear wall of said chamber.

One of the side plates is provided with a slot at 79 through which the empty shell is ejected, and the opposite side plate has a slot at b for a purpose presently explained.

The breech-block .O is provided with a chamber or bore through which a rod 0 passes with a spring 0 which is adapted to press the breech-block forward and close the barrel chamber at the rear end of the barrel. Said rod 0 has a long head 0 threaded in an opening of the rear wall of the casing near its top piece by means of which the pressure of the spring upon the breech-block may be regulated. The spring 0 alone is adapted to control the forward movement and action of the breechblock within the chamber and it is not acted upon by any lever mechanism designed to operate the breech-block, nor is there any locking device used whereby the hammer is temporarily locked so as to'momentarily resist or oppose the rearward movement of the recoiling breech-block. The breech-block is also provided with projecting parts 0 on opposite sides near its front and which extend out through the slots 6 b in the side plates of the'casing and are provided with flat heads 0 whereby the breech-block may be pushed back by hand when desired, the hold of the fingers being upon the heads at opposite sides of the casing and the parts 0 moving in the slots 6 72 The heads are removable, being threaded upon the parts 0 so the breech-block can readily be taken out of the casing when desired. The breech-block further has a groove 0 in one side and a spring extractor-hook 0 on the opposite side to catch the rim of the cartridge shell in the ordinary way for drawing it from the barrel chamber a, and there is a stop pin 6 on the detachable plate B and working in the groove 0 of the breech-block, against which the rim of the shell strikes and the stop pin and extractonhook operate to throw the shell .out through slot 6 when the breechblock is thrown back. Another and preferred feature of the breech-block is a downward projection c from the under side and having a beveled surface at the rear for a purpose presently explained.

The hammer D is pivotally mounted on a pin d which preferably is rigidly fixed to the fixed side plate of the casing and has its free end preferably reduced and entering a hole in the detachable plate 13 The rear wall of the downwardly extended portion of the casing is provided with a recess at (Z which is adapted to hold a V-shaped spring E, one member of which engages with a lug d of the hammer and operates as the mainspring for the hammer, and the other member engages with the long end of the sear F and presses the short end of the sear against the hammer on the side opposite to lug d as seen in Fig. 3. The sear is made of a flat piece provided at opposite sides with trunnions f adapted to enter into holes in the casing side plates and vibrate therein as the fulcrum of a lever. The reverse positions of the hammer and sear are seen in Fig. 4 which shows that the cocking of the hammer increases the bearing of the sear-member of the spring upon the longv end of the sear-lever. The hammer falls upon a spring-pressed firing pin 0 of ordinary form carried by the sliding breechblock.

The trigger G is pivoted in a slot of the front wall of the casing which is provided with an opening at 9 through which a link or slotted sliding trigger bar 9 resting in grooves of the casing side plates with one end bearing against the long end of the sear, and against the sear spring and the other end against the trigger, so that the trigger is adapted to release the hammer in firing.

The casing is provided with an opening at the bottom to receive the magazine H, which when entered can be pushed up until its upper end comes just under the. path of the sliding breech-block. The downwardly-extended portion of the chamber of the casing for holding the magazine is so arranged relatively to the barrel chamber a that the front edge of the magazine falls in a line which at its upper end is forward of the rear end of the barrel chamber, and the lower part of the barrel chamber at the rear is enlarged or cut away as'shown at a to form a downwardly flaring surface from the rear of the barrel chamber into the casing interior and positioned just in front of the uppermost cartridge in the magazine, as seen in Fig. 4. The upper rear part a of the barrel chamber projects straight backward over the enlarged lower part at a The uppermost cartridge can therefore be moved forward and strike said flaring surface at a and have its front end brought into the barrel chamber and under the straight upper part a thereof simultaneously with its being freed from the hold or grip of the magazine and previously to its being raised to the level of the barrel chamber to be pushed into the same.

The upper edges of the magazine side plates for about a inch at the rear are turned in as shown at h Fig. 5 so as to engage the rim of the shell and prevent the cartridges from being forced irregularly out of the magazine by the spring h When the uppermost shell is thus held at the rear in the magazine the projection c of the breeclrblock in its forward movement may come in contact with the rear end of the shell and shove it forward until it is released from the turned-in parts it of the magazine after which it is lifted up in front of the breech-block and thereby shoved into the barrel chamber by the full force of its forward movement. The front and rear walls of the magazine are preferably made lower than the side walls, as shown at b Fig. 4:, so that the projection c passing over said lower parts can extend between the side plates of the magazine at the top. This lowering ofthe front wall also allows the tip end of the bullet to pass into the recess a of the barrel chamber before the cartridge is freed from the grip h, causing it to slide up the flaring surface of said recess in the first stage of its entrance into the barrel chamber.

A spring latch I, pivoted in a recess of the rear wall of the casing, serves to hold the magazine in the casing by engaging a depression at z in the magazine from which it may be released by a counter movement of the opposite end when it is desired to take out the magazine, which has a pin with a head J for taking hold of to pull it out. (Fig. 4.)

The safety device consists of a springpressed lever K pivoted in a slot in the rear wall of the casing and provided with a hook-like point- /c which is adapted to spring back when the hammer is turned back in cooking and engages over the tip end of the hammer so as to hold it until the pressure of the grip on the long end of said lever throws the hook-like end back sufficiently to disengage it from the hammer. This action is produced by the grip of the hand holding the weapon and having the finger 0n the trigger, as when in the act of firing. The rear end of the breech-block may be recessed at 70 to prevent it from striking the hook-like point of the safety device in the back action. -Handle pieces L of wood, vulcanite or any suitable material, are secured to the side plates of the casing by screws.

The operation is as follows: The barrel of the weapon and the casing or frame for holding the working parts are relatively rigid or immovable upon each other. Said casing is provided with a detachable side plate secured by screws so that said side plate is readily removable by anyone accustomed to using firearms for the inspection, cleaning, and oiling of the interior parts without other tools than a small screw driver. The working parts comprising the sliding breech-block, the hammer, the sear, the mainspring and sear spring in one piece, and the trigger-bar are all detachable each from the other and from the casing when the detachable side plate is removed. The sliding breech-block is held securely in place by recesses at the top of the side plates and i is adapted to play back and forth within'the rearwardly-extended upper portion of the chamber coming to a stop in its backward movement against the rear wall of said chamber and in its forward movement against the front wall of said chamber in which the rear end of the barrel comes flush with the, interior of said chamber, the front end of the breech-block closing the rear end of the barrel chamber. The adjustable spring 0 is applied directly to the breechblock and holds it normally closed upon the barrel chamber, and at the instant of firing the force of the hammer and mainspring is added to that of the said spring 0 as operating against the recoil. The recoil, however is sufficient to overcome these unit-ed forces and to throw back the breech-block, cook the hammer and eject the shell, just prior to stopping against the rear wall of the casing. The sliding breech-block works in the rearwardly-extended upper portion of the chamber just above the magazine in the downwardly-extended portion of said chamber and is adapted to engage the rear end of the topmost cartridge and push it forward slightly in the magazine before it is raised therefrom to the level of by the forward movement of the breechblock under the recoil. of the spring 0 The downward projection c of the breech-block in its forward position rides upon the next cartridge in the magazine, holding it down against the lifting action of the magazine spring h during the back action of the breech-block. In its forward position said projection partially closes the recess a of the barrel chamber.

Prior to my invention automatic firearms were made with the frame and chamber in combination with a spring-pressed reciprocating breech-bolt only partially covered by the chamber, and with a frame and chamber in combination with a spring-pressed firing bolt, having a fixed firing spur on its forward end and adapted to be automatically cooked or brought to rest in its retracted position, so that it had to be unlocked by pulling the trigger before it could move forward, to insert a cartridge in the cartridge chamber of the barrel and simultaneously fire it. I therefore do not claim such combination broadly; but

What I claim is:

1. In an automatic firearm, the combination with the barrel of a stock rigidly connected with the barrel and provided with a chamber extended rearwardly in line with the barrel, a breech-block provided with a longitudinal bore and adapted to slide back and forth entirely within said chamber and free of any locking device, and a coil spring within the bore of said breech-block and projected therefrom against the rear wall of said chamber for holding the breech-block normally pressed against the front wall of the chamber over the barrel bore, and permitting it to be reversed by a superior opposite force, for ejecting the shell, without becoming set in its backward position, as specified.

2. In an automatic firearm, the combination with the barrel of a stock rigidly connected with the barrel and provided with a chamber extended rearwardly in line with the barrel, a breech-block provided with a longitudinal bore and adapted to slide back and forth entirely within said chamber and free of any locking device, a coil spring within said bore and projected therefrom against the rear wall of said chamber for holding the breech-block normally pressed against the front wall of the chamber and permitting it to be reversed without becoming set in its backward position, and a rod within said spring having an elongated head threaded in an aperture in the rear part of the frame for regulating the spring pressure upon the breech-block, as specified.

3. In an automatic firearm, the combination with the barrel and chambered frame having rigid connection, of a breech-block provided with a longitudinal bore and adapted to reciprocate freely within the frame chamber, a coil spring within the bore of the breech-block and projected against the rear wall of the frame chamber, a spring-pressed hammer arranged behind the breech-block and a spring sear and trigger for setting and releasing the hammer, as

specified.

4. In an automatic firearm, the combination with the barrel, of a stock frame having rigid connection with the barrel and provided with a chamber for housing the working parts and withan opening in the side of said chamber for ejecting the empty shells, a freely-sliding breech-block provided with a longitudinal bore and a longitudinal groove in the side, a coil spring within the bore of the breech-block and projected against the rear wall of said chamber, and a stop-pin on the side plate opposite from said slot and projecting into said groove about in line with the rear end of said opening, as specified.

5. In an automatic firearm, the combination with the barrel, of a stock frame having rigid connection with the barrel and provided with-a chamber for housing the working parts, a breech-block adapted to slide freely within the limits of said chamber and provided with a longitudinal bore, an extractor hook on the breech-block, a coil spring within said bore and projected against the rear wall of said chamber, and a hammer, main-spring, sear-spring and trigger-bar, inclosed by said chamber, as specified.

GEORGE TOBORG.

Witnesses: Y

ADoLrH J. BORGMEIER,

C. E. BOLDT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

